Hey Chris!

That F# is there in the tab. It's in the 7th bar (second bar of the second set of staff lines). There's actually the D note (3rd fret of the B string) very close to that move to the F# (2nd fret of the high E string) then open B. It's the last 2 notes of that measure.

You may have missed it just because the last note of that open G chord arpeggiation is very close to the walkdown. Hopefully you see it now!

Thanks for the question, keep rockin'!
Mike